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  • 1
    ISSN: 1476-4687
    Quelle: Nature Archives 1869 - 2009
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Notizen: [Auszug] The internal organs of animals often have left–right asymmetry. Although the formation of the anterior–posterior and dorsal–ventral axes in Drosophila is well understood, left–right asymmetry has not been extensively studied. Here we find that the handedness of the embryonic gut and the adult ...
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Morphology 193 (1987), S. 1-11 
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The bursa copulatrix of the silkmoth is filled with various secretions and seminal fluid transferred from the male reproductive system during mating. The contents of the bursa include a pearly body, spermatophragma, and spermatophore. The latter consists of a four-layered wall, an inner and outer matrix, and a soft plug. The components of the spermatophore are all heterogeneous, since they are formed by the partially mixed, viscous streams of the male secretions. Apyrene spermatozoa and eupyrene bundles are present only in the inner matrix, but both the matrices are important sites of sperm maturation. After spermatophore formation, the basophilic regions and periodic acid-Schiff (PAS)-granules in both matrices gradually decrease with time. The PAS-granules were identified as glycogen by α-amylase treatment. The inner matrix containing sperm and the outer matrix decrease in volume and become concentrated near the neck of the spermatophore. Apyrene and eupyrene spermatozoa can move toward the ductus seminalis after their maturation. A large, beltlike space which does not stain remains at the periphery of the spermatophore. These structural changes of spermatophore contents seem to reflect metabolic reactions in the spermatophore as the reactor for sperm maturation.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Journal of Morphology 198 (1988), S. 231-241 
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The penis of the silkmoth, Bombyx mori, consists of two parts covered with cuticle, the corpus penis and crus penis, and a third part, the radix penis, without a cuticle but surrounded by a thick sphincter. The radix penis is divisible into anterior and posterior parts. The ductus (d.) ejaculatorius passing through the penis has no secretory cells. In the anterior radix penis, the wall of the d. ejaculatorius is thin and without folds; in the posterior section, it is thick, with folds in its lumen. The glandula (g.) prostatica is divisible into anterior and posterior parts according to differences in the histological and morphological characteristics of the cells and their secretions, which contain many heterogeneous substances. In the anterior g. prostatica, secretions accumulate separately in the anterior and posterior sections before ejaculation. Unlike the posterior region, the anterior region displays a large mass(es) at the periphery of the lumen along the secretory cell layer. Judging from staining properties, the pearly body and the first layer of the spermatophore wall, which, after copulation, form in the female bursa copulatrix, seem to be derived from the secretions of the anterior and posterior regions of the g. prostatica, respectively. The secretion of the posterior g. prostatica contains initiatorin, which acts as a sperm-activating factor in the inner and outer matrices of the spermatophore. An ejaculatory valve is found between the radix penis and the g. prostatica. The opening of this valve is regulated by the surrounding sphincter, thus impeding the back-flow of secretions and seminal fluid in the radix penis and resulting in their transport outwards during ejaculation. The musculature of the d. ejaculatorius and the corpus penis promotes further transport of these secretions into the female bursa copulatrix.
    Zusätzliches Material: 21 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Journal of comparative physiology 155 (1985), S. 653-657 
    ISSN: 1432-136X
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Arginase activity was studied in the silk-worm,Bombyx mori. 1. The specific activity remained low from the larval to mid-pupal stage in both sexes. In males, it then increased markedly in the late-pupal stage, reached a maximum in young adults, and then gradually decreased with age, whereas in females it remained almost constant throughout development and ageing (Fig. 1). 2. Of all organs of both sexes, the vesicula seminalis of adult males had the highest arginase activity, the activity in this organ amounting to 95% of the total activity in adult males. The specific arginase activity in this organ was at least 50 times those in other organs. The enzyme activity in the vesicula seminalis increased very greatly during metamorphosis to adults (Tables 1, 2, 3). 3. When the vesicula seminalis was incubated withl-[14C(U)]-ornithine, large amounts of radio-activity were found in the metabolites proline and glutamate, suggesting the conversion of ornithine, produced by arginase, to proline (Fig. 2, Table 4). 4. Proline and succinate were effective substrates for the respiration of silkworm spermatozoa, whereas glucose, α-glycerophosphate and pyruvate were not used.
    Materialart: Digitale Medien
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